I'd be really interested to hear what you think - I've got a professional and a personal interest in this question.
Personally I feel quite strongly that if two people decide to have a child they should accept that they need to live as close as possible to each other so that the child gets the benefit of both of them, at least while the child is little. Otherwise, how does that child get to have a relationship with the parent that he/she doesn't live with?
I had one case where the mother of a one year old said she was moving to Australia - no real reason why she couldn't have waited a few years (she had family out there to live with) until the baby could at least talk and therefore be able to speak to his dad on phone/web cam etc. by making that decision she made sure her son wouldn't know his father as neither of them could afford to fly back and forth more than once a year. The court gave her permission to go.
I feel very strongly this is just wrong and I think the courts should reflect this and only allow parents to leave the country in exceptional circs, at least while the children are, say, under 10.